He made his final major appearance at the 2010 European Athletics Championships and announced his international retirement at the end of that year.

[3] The 2001 season marked an improvement in his performances: he set a personal best and Swiss record in the steeplechase with a time of 8:22.24 at the FBK Games in Hengelo in July.

[3] A month later he competed at the 2001 Summer Universiade and had his first international podium finish, taking the bronze medals in both the steeplechase and 5000 metres.

[5] At the end of the year he participated at the 2001 European Cross Country Championships, held on home turf in Thun, and he took fifth place in a field of 77 runners.

He was the best Swiss performer at the event, heading the national team (including Viktor Röthlin) to seventh in the rankings.

[11] He returned his focus to the track and reached the 10,000 m final at the 2010 European Athletics Championships in Barcelona, finishing in sixth place.

Belz announced his retirement from international competition at the end of 2010, citing his desire to focus on both his family and his work as a specialist in sports economics.